a {
    display: block;
    margin: 25px;
    text-decoration: none;
    padding: 15px;
    color: #0033FF;
}

a:hover {
    padding: 15px;
    display: block;
    margin: 25px;
    border-radius: 10px;
    background-color: #cccccc;
    text-decoration: none;
}

.list_parent {
    list-style-type: none;
    padding: 0px;
}